Primate core will provide the required experimental animals and support services needed to facilitate the AIDS vaccine development studies proposed. The Specific Aims will be to: Provide retrovirus-free (SIV, STLV-I, SRV) and herpes virus B- free rhesus macaques. Generate a titrate a SHIV stock that encodes the env gene of a primary Chinese HIV clade B'/C strain; Test the safety, immunogenicity, and efficacy of candidate AIDS vaccines in macaques; and Test the safety, immunogenicity and efficacy of cytokine adjuvants for DNA vaccines and macaques. Core will perform daily monitoring of the experimental animals, conduct physical examinations, collect blood to assess the animals' clinical condition and to provide specimens for laboratory evaluation, and perform complete gross and histologic evaluations of all experimental animals. Core will also assess humoral and cellular immune responses generated by the vaccinated animals and perform viral challenge experiments. For virus-exposed animals, Core will perform flow cytometric evaluations to determine lymphocyte subsets, real time RT- PCR assays to evaluate plasma viral RNA loads, and virus isolations. Provision of these resources and support services will allow project 3 to test a novel SHIV construct encoding a primary env gene that is highly prevalent in China. Core will also facilitate the development and testing and of the candidate AIDS vaccine strategies described in Project 5 of this application. The proposed virologic and clinicopathologic evaluations, in concert with the immunologic studies, will allow assessment of vaccine efficacy with respect to vector replication, immunogenicity and prevention of infection or modification of post- challenge viral loads or set points.